Dr Robert Drummond BChD, DipOdont Ortho, MChD(Ortho), FDC(SA) Ortho

Canad Inn Polo Park

Winnipeg

2015

Severely compromised FPM with poor prognosis

Children often present with a developing dentition

affected by one or more first permanent molars of poor

prognosis, which may require their enforced extraction

In the right circumstances, first permanent molar extraction can

be followed by successful eruption of the second permanent

molar to provide a suitable replacement, and ultimately third

molar eruption to complete the molar dentition, although this is

not guaranteed

Should the compromised FPM be extracted as soon

as possible, or should it be temporarily restored

and extracted later?

If the prognosis of one FPM is poor, is extraction of

the other FPMs required?

National clinical guidelines for the extraction of first permanent molars in children. M. T. Cobourne, A. Williams and M. Harrison. British Dental Journal, Volume 217 no. 11, DEC 5 2014.

The best available evidence

Condition that will influence the clinical management Comprehensive patient examination Importance of Panoramic Radiograph Diagnosis Definitions

Balancing Extraction Compensating Extraction

Ideal Timing Orthodontic Opinion Guideline for elective FPM extraction in children with different

malocclusions General rule Class I with no crowding Class I with crowding Class II with no crowding Class II with crowding Class III

Trial Case Conclusion

The individual patient circumstances

Maxilla or Mandible

The extent of crowding and the presenting malocclusion If the patient will require or desire orthodontic treatment in

the future, the timing and extraction pattern should be tailored to achieve the optimal outcome for that individual patient

The stage of dental development

Any other permanent teeth absent, severely displaced or of doubtful prognosis

Other pathology

Facial analysis

Facial Symmetry

Facial Proportions

Profile

Lips

Smile

Intra-oral analysis

Radiographic examination

Panoramic radiograph

Before any decision is made, a panoramic radiograph of good quality is needed to show that all teeth are present, in good condition i.e. not hypoplastic, and are well placed for eruption

Malocclusion Antero-posterior (AP)

Transverse

Vertical

Crowding Amount

Anterior or posterior

Arch Symmetry

Dental development

Contemporary Orthodontics, 5th edition. William R. Proffit, Henry W. Fields

Balancing extraction

Is the removal of the first molar on the other side of the same arch

Compensating extraction

Is the removal of the first molar on the same side in the opposing arch

In the maxilla, an unerupted 7 with a decent developmental position at the time of extraction of the FPM, generally ensures a good occlusal position

In the lower arch timing of the extraction is more important for successful eruption of the 7’s

Chronological age between 8 and 10, after eruption of the lateral incisor’s and before the eruption of the second molars and /or second premolars

Also if there is radiographic evidence of early dentine calcification within the second molar root bifurcation

Extractions before the age of 8 should be avoided:

As normally, there is no radiographic evidence of third molar development

Second premolars can escape from its position between the roots of the e’s and therefore drift distally

Labial segment can retrocline , increasing the overbite and overjet

Extraction during the later stage of second molar development

Mesial tipping

Rotation

Spacing

Poor occlusal contact

Ideally an orthodontic opinion should be obtained before extraction of any permanent tooth; if possible from the orthodontist who will be responsible for future treatment

Temporise or restore and refer

This is not always possible if there is sepsis or pain

Guideline for Elective FPM Extraction in Children with Different Malocclusions

General rule

Class I with no crowding

Class I with crowding

Class II with no crowding

Class II with crowding

Class III

As a general rule, if in doubt, get the patient out of pain, try and maintain the teeth and refer for a specialist orthodontic opinion

In recent years, fixed anchorage devices have become more routinely available in orthodontics and these provide further options in the management of first permanent molar extraction cases, particularly in terms of anchorage reinforcement and space closure

Aim for extraction at the optimal time for eruption of the second permanent molars into a good position

Do not balance unilateral first permanent molar extraction in either the upper or lower jaws if the first permanent molars are healthy

If the lower first permanent molar is to be lost, the

opposing upper first molar can over-erupt as a result

Prevent over-eruption with a simple appliance

Compensating extraction of the upper first molar can

be considered if this tooth is likely to be unopposed

for a significant length of time

If over eruption did occur, molar intrusion with TAD’s during full fixed orthodontic treatment

is possible

If the first molar on the lower arch is to be extracted and the opposing upper first molar has a poor prognosis, consider extraction of this tooth

If the upper first molar is to be extracted, do not compensate with extraction of the lower first molar if it is healthy

16 54 lost

Middle mixed dentition– with caries on several teeth All permanent teeth present, not all erupted Minimal crowding Early loss of 54 with space maintainer Mesial drifting 16 – localized space shortage, 1ste Quadrant Heavily restored 16 with questionable prognosis Extensive caries 46 = poor prognosis ( Dentist requested opinion on the XLA) Advance development of the 7’s - 2/3 root formation Radiographic evidence of the development of all four third molar

16 54 lost

Middle mixed dentition All permanent teeth present, not all erupted Minimal crowding Early loss of 54 with space maintainer Mesial drifting 16 – localized space shortage, 1ste Quadrant Heavily restored 16 with questionable prognosis Extensive caries 46 = poor prognosis ( Dentist requested opinion on the XLA) Advance development of the 7’s - 2/3 root formation Radiographic evidence of the development of all four third molar

16 54 lost

Extraction 46, 16 & 55

NB! Due to the advanced development of the 47, extraction of the 46 could result in poor occlusal contact for the 47 with increased mesial tipping and spacing and a higher need for orthodontic correction

BUCCAL SEGMENT CROWDING

ANTERIOR CROWDING

BUCCAL SEGMENT CROWDING

Aim to extract at the optimal time to allow eruption of second molars into a good occlusal position, which should also provide some relief of crowding

If the buccal segment crowding is bilateral, consider balancing extraction of the contralateral first permanent molar to provide suitable relief, particularly if there is any question regarding the long-term prognosis for this tooth

Compensating extractions of upper first permanent molars can be considered to relieve premolar crowding

Buccal crowding and severely compromised 46 and 36

Extraction of the 46 and 36

With 7’s replacing the 6’s with good axial inclination and occlusal contact

All four permanent molars were compromised and subsequently extracted, which resulted in 7’s replacing the 6’s with good axial inclination and occlusal contact

Relieve of the buccal crowding

ANTERIOR CROWDING

In the presence of crowding in the labial segments, little

spontaneous relief is provided by first permanent molar extraction

First permanent molar extractions can be delayed until the second permanent molars have erupted and then the extraction space can be used for alignment with fixed appliance

Alternatively, first permanent molars can be extracted at the optimum time and the crowding treated once in the permanent dentition

If premolar extractions are likely to be required at this stage, the third molars should be present

• Hypermineralized upper & lower FPM with secondary Caries

Moderate upper crowding

Potential eruption problems with

upper canines

Severe lower crowding

Class I buccal occlusion left and right

Mandibular midline 3mm to the right

Unerupted 42 & no space

Normal overjet and overbite

?

?

Confirm possible ectopic 13 and 23 and possible impaction of the 43

Radiographic evidence of only the 48 and 28

Beginning root formation on the 7’s

x

x

x

x

• Extract the first permanent molars at the optimum time to allow for the permanent second molar to replace 6’s

• Resolve the crowding, once in the permanent dentition • For which you will need additional four premolar

extractions : which does not make this option ideal • There is also no clear evidence on the presence of two of the

third molars which is a contradiction for this option

x

x

x

x

Delay first permanent molar extractions until the second permanent molars have erupted and then use the extraction space for alignment with fixed appliance

x

x

x

x

• Option 2 • Temporarily restore the 6’s • Wait for the eruption of the 7’s • After eruption of the 7’s extraction of all four FPM • Full fixed orthodontic treatment with additional anchorage

The extraction of first permanent molars in Class II cases are more difficult to plan, particularly with regard to the upper first permanent molars

The main complicating factors in the upper arch is the need for space to correct the incisor relationship

Class II

Growth modification / non-extraction

Camouflage Extraction upper 4’s

and or lower 5’s

Fixed

Removable

Combination Growth modification

& Extractions

Distalization

Class II Growth

modification / non-extraction

Fixed

Removable

Extract the first permanent molars at the optimum time to allow for the permanent second molar to replace 6’s

The patient should be counselled however, that additional premolar extractions in the upper arch might be required in the future to create space for overjet correction if the GM is unsuccessful

Class II Camouflage Extraction upper 4’s

and or lower 5’s

Distalization

•

The upper first permanent molars should be temporised or restored so that their extraction can be delayed until the second permanent molars have erupted

The resultant extraction space can then be used to correct the malocclusion with fixed appliance

The extraction of the lower first permanent molar should be carried out at the ideal time for successful eruption of the second permanent molar in its place

Class II

Combination Growth modification

& Extractions

The upper first permanent molars should be temporised or restored so that their extraction can be delayed until the second permanent molars have erupted

The resultant extraction space can then be used to correct the malocclusion and crowding with fixed appliance

The extraction of the lower first permanent molar should be carried out at the ideal time for successful eruption of the second permanent molar in its place if the crowding is in buccal segment

If the crowding is anterior delay the extraction until after the eruption of the 7’s

Camouflage Extraction upper 4’s

and or lower 5’s

Distalization

Class III cases are often difficult to manage and ideally require the opinion of a specialist orthodontist before any first permanent molars are extracted

As a general rule, extraction of maxillary molars should be avoided if at all possible, while balancing and compensating extractions are not recommended in Class III cases

A tendency toward increased residual spacing has been described in the lower arch of Class III cases following first permanent molar extraction

Treatment planning for the enforced extraction of first permanent molars can present a complex problem, particularly in the presence of an underlying malocclusion

I hope these guidelines will be useful in your decision making

If you have any questions you are welcome to contact me at robert.drummond@umanitoba.ca